Question: How is the production of a cell wall encoded (or not) in DNA in a cell's replication process?
What's a virus, anyway? The bare-bones basics
161–170 of 202 posts
Re: What's a virus, anyway? The bare-bones basics
#162> Is a virus a living thing? Maybe. I remember 20 year ago, at school, when the biology teacher was presenting this dilemma. Ever since, when I hear someone saying "doing this will kill the virus", it triggers my brain into this subject, since you can't kill something if it's not alive ;) Somewhat related, I also like the concept of the "Viruses of the Mind" [1], which makes an analogy between the spreading of a biol…
I prefer the names "memetics" to talk about the field of infectious ideas and "memetic agents" when talking about single instances. A "memetic agent" is something like a virus, just replicating in minds instead of meatspace.
The SCP wiki started these terms to refer to objects which present anomalous properties when you're exposed to them, such as what the foundation regularly employs to protect articles; "memetic kill agents", basically information that kills if you consume it.
Re: What's a virus, anyway? The bare-bones basics
#163Earlier quoted context omitted.
Process reproduce (through forking) metabolize (stdin->stdout) and maintain homeostasis (garbage collection). How could they not be alive?
(Morally) Because reproduction without purpose is not life. Necessary but insufficient.
The purpose of a virus is to replicate.
The purpose of a bacteria is to replicate. They just do it the complicated way.
That goes up all the way to modern humans; on a ground level, life is about replicating your genetic information. What you do beyond that is on you.
Re: What's a virus, anyway? The bare-bones basics
#164Earlier quoted context omitted.
I wouldn't recommend trying to understand it through analogy to CS - I'm a biologist and know enough CS to feel uncomfortable really using any of the usual analogies. The problem is that they work ok for a layperson understanding, but are fundamentally wrong enough that if you want to understand it at the level of something like virology you'll be lead constantly astray. I dont know of a better recommendation than "w…
Can you recommend any sites like HN, but for biology?
I dont actually know of any. I've heard of like biostar and maybe a couple others but I dont know how good those are. Researchgate is kind of a forum I guess? But most of the questions I've seen in the social media side of that are like "how do I turn this experiment"
I think most of the discussions I've had have been journal clubs during lab meetings. An hn style website for virtual journal clubs would be super cool...
Re: What's a virus, anyway? The bare-bones basics
#165> Try multiplying a billion billion billion billion by a trillion trillion trillion trillion, then multiply that by a thousand, and that (10 to the 31st power) is the mind-numbing estimate of how many individual viral particles are estimated to populate the planet. What definitions of "billion" and "trillion" are they using? 10 to the 31st would be only ten million trillion trillion, going by the common definition of…
4 x 9 + 4 x 12 + 3 = 87 4 x 3 + 4 x 4 + 3 = 31. That’s the only genesis of this error I could come up with - somehow they associated billion with 3 and trillion with 4 (conceivably because “N-illion” = 1000^(N+1) [1], and then forgot about the factor of three embedded in the base of 1000). [1] in the US system. In Germany and historically the UK, apparently, it’s 1000,000^N = 1000^(2N), which I personally prefer.
In germany the step size is twice as large; million, milliard, billion, billiard, etc. Makes things neater IMO.
Re: What's a virus, anyway? The bare-bones basics
#166Earlier quoted context omitted.
The problem with including codons in such a high level analogy of DNA is their context sensitive. DNA doesn’t care about those details and can be sliced an diced to completely change how it’s interpreted. Also, you really should include activation sites etc, but soon your out of the realms of analogy and just describing the details.
The big component missing in the analogy is gene expression. That’s what makes DNA behave differently from simple instruction mappings. I guess we could visualize it as a series of drains, where the size of the hole can be modulated. Since gene expression can decrease or increase the rate at which DNA is transcribed
I have been using this for a while. What would you suggest instead of:
> The workers, raw materials, and signals to turn sections on or off are separate.
People are used to the idea of thermostats using on/off to maintain temperature which is not a terrible association. As you say gene expression is different, but I can’t find a better analogy.
Re: What's a virus, anyway? The bare-bones basics
#167Earlier quoted context omitted.
> It never translates it's RNA and since RNA is fundamentally less stable of a molecule than DNA, you get really high mutation rates. That "instability" is caused by the lack of a built in error checking mechanism in RNA. The coronovirues have a proofreader mechanism, which is interesting. And influenza has more potent evolved countercountermeasures than just high mutation rates: https://en.wikipedia.org/wiki/Antigen…
Yep! That's what really makes influenza special, as I said the mutation rates are only part of why Influenza viruses rapidly change. Their ability to cross between species by combining easily with other types of influenza viruses are the key to their incredible variability One of the distinguishing trait of CoVs are their special RNA replication/transcription mechanisms that results in less errors, which is really im…
> Though, and correct me if I'm wrong, aren't they still extremely less stable than DNA viruses?
That's correct. Worse, the proofreader doesn't have to protect all parts equally...
> Which is why only short/medium term immunity is usually possible?
No. For some viruses active immunity just doesn't last particularly long for reasons we don't understand (or at least it was described as not understood in every paper I've seen on the subject). For some viruses you can be reinfected months later with exactly the same virus. This is the case for several cold causing viruses.
Re: What's a virus, anyway? The bare-bones basics
#168Someone who is a molecular biologist, please correct my understanding. DNA is a molecule, made out of 4 amino acids. ACTG. There are 18 different kinds of amino acids. Amino acids are made out of carbon, nitrogen, hydrogen, oxygen. Amino acids make proteins. Proteins are the structural bricks (like LEGO) that are combined in various sequences by enzymes to build more complex machinery. The proteins make up cell organ…
DNA is made of nucleic acids (deoxyribonucleic acids), not amino acids. DNA is translated to amino acids, except when it encodes long-noncoding RNAs, or miRNAs, or piRNAs, or untranslated regions, or intergenic regions, or transposons, or psuedogenes. And the protein coding sequences are coded into proteins, except when there are alternative splicing sites, or anti-sense RNAs. And then the protein sequence folds into…
As an outsider, microbiology is hopelessly complex.
Re: What's a virus, anyway? The bare-bones basics
#169Earlier quoted context omitted.
what’s the purpose of an amoeba? or a mosquito? or a duck? or a chimpanzee?
Would you not say they each have more purpose than a virus?
Definitely not. Viruses perform key roles in ecosystems, particularly in ocean ecosystems. Their infection and subsequent killing of organisms provides a vital mechanism for cycling nutrients. They also help keep algal blooms in check. Viruses kill 20% of bacteria in the oceans everyday.
Viruses also provide a mechanism for horizontal gene transfer. A protein that is critical to the formation of the human placenta has a viral origin.
Viruses have a massive impact on life, but we're just now starting to realize it.
Re: What's a virus, anyway? The bare-bones basics
#170Is there a a good read on how RNA and DNA work for a Computer Scientist? And more generally how biology, genetics, epigenetics, virus, etc work? Many vulgarization sources say that DNA is like the source code of life. But they mostly skim across the issue and go to conclusions like "this gene or set of genes are responsible for that outcome". But coming from a CS background that sounds a bit like non-sense. I feel li…
DNA seen through the eyes of a coder: https://berthub.eu/amazing-dna/
Molecular Biology Made Simple and Fun https://www.amazon.com/dp/1889899070